Sound and vision blog

Cheryl Tipp, Curator of Wildlife & Environmental Sounds writes:

The Common Wasp (Vespula vulgaris) gets a pretty bad rap. We’re all in love with bees but, when it comes to wasps, we’re not so enamoured. To be fair, they don’t help themselves. They fall into your pint, pester you at picnics and seem to sting you just for the hell of it. Despite these little niggles, wasps do play an essential role in the smooth running of our ecosystems.

As predators they help control pests which would otherwise wreak havoc in our crop fields and gardens. Their quest for nectar makes them valuable pollinators too; as they move from flower to flower, they transfer life-giving grains of pollen that become stuck to their hairy bodies.

Their social lives are just as interesting. Every spring the queen emerges from hibernation and goes in search of a suitable site for the colony’s new nest. Once selected, she begins to lay the foundations of the nest, using chewed wood fibres to create a core into which she will eventually lay her eggs. Upon hatching, the newly-developed adults take over the building of the nest, leaving the queen to oversee the colony and produce more eggs.

The following recording takes you into the very heart of a working wasp nest. The constant buzz and crackle of activity is accompanied by a repetitive fluttering of wings as workers busy themselves with fanning the nest's precious eggs. This fanning action helps circulate the air inside the nest, providing a fresh and cool environment for the colony to thrive in.

Wasp nest activity recorded in Dorset, England on 1 Aug 2000 by Kyle Turner

Though it seems unlikely that wasps will ever hold the same place in our hearts as bees do, there can be no doubt that these little insects are a fascinating and essential part of the natural world. So the next time a wasp takes a keen interest in your beer or slice of sponge, try not to judge it too harshly.

Follow @CherylTipp and @soundarchive for all the latest news. This recording is being preserved as part of the Library's Unlocking our Sound Heritage project.

This week's selection comes from Cheryl Tipp, Curator of Wildlife and Environmental Sounds. 

The sound archive is home to over 250,000 wildlife recordings from all over the world. Over 100,000 of these are recordings of birds. As a curator it’s impossible to have a favourite when surrounded by so many choice examples, however I do find myself returning to certain recordings time and time again.

One of my ultimate favourites is the song of the Montezuma Oropendola (Psarocolius montezuma). This central American songbird inhabits lowland forests and plantations from Mexico to Panama. Individuals congregate in basket-like nests which hang down from the canopy like baubles on a Christmas tree. The male song is an increasingly excitable stream of gurgling notes, produced as part of an acrobatic mating display. Male birds deliver their song from a favoured perch while flipping upside down and waving their tail feathers in the air. Some have been known to get so carried away that they've actually fallen off of their perch. Embarrassing. 

The following song was recorded in Heredia Province, Costa Rica on the 2nd March 1985 by Richard Ranft.

Montezuma Oropendola song (BL reference 15868) 

Photo credit: J. Amorin on Visual Hunt / CC BY-NC-SA

Thanks to the Heritage Lottery Fund, this recording has been digitised and preserved for the nation as part of the British Library's Unlocking our Sound Heritage project. And if you'd like to hear more weird and wonderful wildlife sounds, pay a visit to the Environment and Nature section of British Library Sounds. 

Follow @CherylTipp and @soundarchive for all the latest news.

Greg Green, Audio Project Cataloguer for Unlocking our Sound Heritage writes:

In this digital age, most of us are familiar with audio waveforms, the ‘wavy’ images that represent the dynamic course of a particular sound recording. Waveforms are in fact a type of graph, with time on the X axis and amplitude (or loudness) on the Y.

Figure 1: a waveform represents a sound recording by showing amplitude over time

Waveforms are very useful for conveying basic information about a recording e.g. where the loud bits are, where the quiet bits are, and how dynamic the recording is. If you were listening to an interview, a waveform can clearly show you where someone is speaking. Unfortunately, waveforms cannot tell us much about the pitch, frequency, or harmonic content of a recording. For that we can use a different visual representation of sound… say hello to the spectrogram!

How to read a spectrogram

Spectrograms keep time on the X axis but place frequency on the Y axis. Amplitude is also represented as a sort of heat map or scale of colour saturation. Spectrograms were originally produced as black and white diagrams on paper by a device called a sound spectrograph, whereas nowadays they are created by software and can be any range of colours imaginable!

Figure 2: waveform and spectrogram of the same recording. An oscillating low frequency buzz dominates the waveform, only the spectrogram reveals where the bird is calling

Spectrograms map out sound in a similar way to a musical score, only mapping frequency rather than musical notes. Seeing frequency energy distributed over time in this way allows us to clearly distinguish each of the sound elements in a recording, and their harmonic structure. This is especially useful in acoustic studies when analysing sounds such as bird song and musical instruments. So not only do these graphs look really cool, but they can tell us a lot about the sound without even listening.

Figure 3: a spectrogram showing the harmonically rich calls of whooper swans

Whooper Swan calls recorded by John Corbett (BL shelfmark WS1734 C5)

In the above example, we can see the calls of a Whooper Swan represented in a spectrogram. The fundamental frequency of the calls is at about 750Hz, which is the frequency with the most energy (usually the lowest frequency of a sound), and gives the sound its perceived pitch. Above that are the harmonics - additional, quieter frequencies that give the sound its ‘colour’ and make up a sort of sonic signature – a Whooper Swan singing a perfect ‘G’ note will have a very different harmonic structure to a piano playing that same note. This information could be used to analyse bird songs and calls in different locations, or to understand the vocabulary of a species.

Creative uses for spectrograms

Clearly spectrograms can tell us a lot about the acoustic elements of a sound, but they are not just used for scientific studies. Audio editing is most often performed with waveforms as it's easier to make cuts or process a selected time range. When editing software uses spectrograms however, it opens up a whole new realm of possibilities! With this spectral editing, we are able to look into the microscopic details of a sound and apply processes to very specific time and frequency ranges. For example, an obtrusive footstep, or car alarm could be identified and removed from a recording, just like ‘photoshopping’ sound!

Figure 4: a recording of a robin singing was ruined by a dog barking and some low end noise – a spectrogram reveals the unwanted noises and allows the recordist to remove them.

Spectral repair BEFORE

Spectral repair AFTER

Musicians can also use spectral editing to compose and generate sounds that could not be made any other way. Patterns and shapes can be ‘drawn’ into spectrograms and played back as frequency content. In some cases, detailed graphic images can be hidden within spectrograms. Aphex Twin used this technique to hide an image of a face within the second track of his ‘Windowlicker’ EP (1999).

You can find some more examples of images hidden in the spectral content of popular songs here: https://twistedsifter.com/2013/01/hidden-images-embedded-into-songs-spectrographs/

So now you know what spectrograms are, how to read them, and some of their many scientific, creative, and bizarre uses. Keep an eye out for our #SpectrogramSunday @BLSoundHeritage tweets, starting this weekend!

Coleridge Research Fellow Dr Alice Rudge writes:

The Batek are hunting and gathering people who dwell in the lowland rainforests of Peninsular Malaysia. During my fieldwork with them, I played  some recordings of mammal sounds which are held at the Library. Batek people have extremely detailed ecological knowledge of the rainforest, and this is reflected in their in-depth understanding of its soundscape. I therefore played them these recordings with the idea that hearing these sounds might inspire people to give additional vocabulary or information about these sounds, based on their extensive knowledge.

You can listen to the recordings below:

Siamang duet recorded on Sumatra by Ashley Banwell (BL ref 62323)

White-handed Gibbon calls recorded in Malaysia by Reg Kersley (BL ref 06512)

Clouded Leopard calls recorded in Thailand by John Moore (BL ref 128288)

Binturong calls recorded in Thailand by John Moore (BL ref 61103)

Not only were people aware of what the animals were doing in the recordings I played, but they also accompanied this with cultural information, as well as talking about the emotions that hearing the sounds evoked.

For example, people said that the siamang and white-handed gibbon in the recordings are all running away from predators. In addition, they pointed out that in the siamang recording, the low sounds are the males, but the higher sounds are the females. 

In response to the siamang and white-handed gibbon in particular, people also exclaimed that they felt haʔip ­- an intense feeling of longing, yearning, love, or desire, which is often felt in response to things that are considered beautiful.

Siamang; Symphalangus syndactylus

The beauty of these mammal sounds is reflected in people’s musical instrument playing. The siamang is a favourite sound to recreate on the mouth harp, and the white-handed gibbon is a favourite sound to recreate on the flute. 

However, as well as feeling haʔip,  the white-handed gibbon recording also prompted people to tell the story of the gibbon, including the gruesome part at the end where evil cannibals cook and eat their mother-in-law, which resulted in everyone falling about laughing.

White-handed gibbon; Hylobates lar

People recognised the sound of the clouded leopard as the yah bintaŋ - yah means ‘tiger’ in Batek, and bintaŋ (or bintang) is the Malay word for ‘stars’, referring to the pattern of its fur.

Clouded leopard; Neofelis nebulosa

In the binturong recording, they said that the female binturong is ‘trying to attract male binturongs to mate with’ (ʔoʔ ʔajak tmkal ʔom cycəy).

Binturong; Arctictis binturong

As is also the case for recordings of birds, using wildlife recordings of mammals in the field can therefore be useful for anthropologists, ethnomusicologists, or others who may be interested to find out more about how these sounds are experienced!

The Alice Rudge Collection of Batek recordings is currently being deposited and catalogued, and will be held under the shelfmark C1773.

Cheryl Tipp, Curator of Wildlife and Environmental Sounds, writes:

In Disney’s The Lion King, the young cub Simba finds himself in the midst of a terrifying wildebeest stampede. Though our little hero survives the ordeal, a stampeding herd of wildebeest is certainly a force to reckon with.

Every year during the great migration, over one and a half million wildebeest leave the calving grounds of the Serengeti for the lush grazing pastures of the Maasai Mara. This journey from Tanzania to Kenya spans over 1,800 miles and is part of an endless cycle of movement that sees wildebeest, along with other animals such as zebra and gazelle, constantly on the move in search of fresh food and water. Though relatively sedate at times, it doesn’t take much to send this huge mass of bodies into a frenzied panic. All it needs is a whiff of danger.

In 1988, French field recordist Claude Chappuis recorded a herd of stampeding Blue Wildebeest (Connochaetes taurinus) in the Maasai Mara. The accompanying recording notes make no mention of what caused the herd to take to their heels. Were they spooked by the presence of the recordist? Had a pride of lions or a solitary leopard been spotted nearby? And where was the recordist positioned while all of this was taking place? Was he in a nearby vehicle? Or on the ground? We assume that Chappuis and his equipment were safely out of harm's way, but with no contextual information to refer to, all we can rely on is our imagination. So sit back, close your eyes and picture the scene.

Stampeding Blue Wildebeest recorded by Claude Chappuis (W1CDR0000816 BD25)

This recording, along with tens of thousands of other wildlife examples, will soon be digitally preserved as part of the library’s Unlocking our Sound Heritage project.

Cheryl Tipp, Curator of Wildlife and Environmental Sounds, writes:

There are plenty of positives when it comes to digitising archival sound recordings. Long term preservation and improved access are top of the list, however the opportunity to easily explore thousands of freshly digitised files is a curator’s dream.

The library’s Unlocking our Sound Heritage project has digitised an impressive 18,000 wildlife recordings over the past 12 months and this has brought a range of interesting content to the surface. One of our recent favourites is a nocturnal recording of Golden Plovers in the highlands of Scotland. The recording is wonderfully atmospheric, with Red Grouse and Snipe adding to the moorland soundscape. Yet this isn't the only thing that caught our attention. The accompanying metadata, provided by the recordists Charles and Heather Myers, demonstrates the difficulties of recording wildlife in the dark, especially when you encounter unexplained sounds.

Though our Golden Plover recording is dominated by bird calls, it also contains the grazing sounds of an unidentified animal. Charles & Heather were both accomplished naturalists and could identify the songs and calls of British wildlife with ease. Non-vocal sounds however, such as movement or eating, could leave even the most talented individual stumped.

You may be thinking "But couldn't the recordists just take a peek in the direction of the sound?" The answer is, not easily. The recording was made on remote moorland in the dead of night. In addition, the microphones had been placed over 45 m away from the camper van where their recorder was being operated. The only thing left to the Myers' was the power of deduction, as can be seen in the following recording note:

"As I was unsighted it is all guess work. But one thing is certain: the birds were very close. There were Red Deer about so I assume the grazing sound was made by one of these (was it a swishing tail that caused the bump on the mics?) You can hear him stop grazing & trot away to the right (3 min. 13)" 

Golden Plovers with possible Red Deer grazing nearby, recorded on 28th April 1989 in the Scottish Highlands (BL ref 20173)

 Could a hungry Red Deer be the source of our unexplained grazing sound?

We'll never know whether the Myers' did record a Red Deer grazing on the moorland turf. Unidentified sounds are often part and parcel of the field recording process, so it's down to the recordist (or the curator!) to fill in the blanks. But, at the end of the day, that's all part of the fun.
 

Follow @CherylTipp for all the latest wildlife news.

Have you ever noticed how some animals are named after people? Hume's Partridge. Lady Amherst's Pheasant. Waller's Starling. I come across this quite a lot when cataloguing new collections and have often wondered who these people were.

You'd be forgiven for thinking that these species were named after the naturalists who discovered them. Now, there are no rules that say you can't name a new species after yourself, however it's generally regarded as bad form in most taxonomic circles. Helps keep the egos in check etc.  It's perfectly acceptable to name a species after somebody else though. Most names are given as a declaration of admiration or love, however a few have been chosen out of spite. What better way to insult a critic or a rival than by naming a disagreeable specimen after them? Carl Linnaeus, the father of modern taxonomy, was the king of the nomenclature slap down. Mess with Linnaeus and you could be sure that a smelly weed or a boring nettle would soon bear your name.

In this particular example we're going to look at Mrs Boulton's Woodland Warbler, Seicercus laurae. Now more commonly referred to as Laura's Woodland Warbler, this little songbird can be found in the dry forests and swamps of central Africa. The species was discovered in 1931 by the American ornithologist W. Rudyerd Boulton (1901-1983) who specialised in the avifauna of Africa. While assistant curator of birds at the Carnegie Museum of Natural History, Boulton made several research trips to Africa accompanied by his first wife, the ethnomusicologist Laura Crayton Boulton (1899-1980). It was with Laura that he discovered this previously unknown warbler which he named in her honour.

Laura's Woodland Warbler, recorded at Mount Namba, Angola by Michael Mills (BL ref 163291) 

The Boultons continued to explore the ornithological and musical treasures of Africa until the mid 1930s when their marriage began to fall apart. The couple finally divorced in 1938 and, though Laura continued in the field of ethnomusicology, Rudyerd's professional life took an entirely different turn. In 1942 he joined the African branch of the Office of Strategic Services (OSS), the US intelligence agency formed during World War Two, where his knowledge of the landscape, people and politics of central African countries was put to good use. In the same year he married his second wife, the socialite, poet and psychic Inez Cunningham Stark. Though mainly based out of Washington DC, Boulton was heavily involved with operations in the Democratic Republic of the Congo, most notably the procurement of uranium ore for the Manhattan Project.

At the end of WWII, Boulton continued working in intelligence for several years, including a stint with the CIA, until, apparently at least, turning his back on espionage in 1958. A year later he created the charitable Atlantica Foundation with his third wife, the wealthy widow Louise Rehm. The remit of this foundation was broad but ambitious, aiming to establish and support research into zoology, ecology, fine arts and parapsychology. The couple based their operation out of Zimbabwe and were by all accounts generous supporters of research and education in the area until their deaths in 1974 (Louise) and 1983 (Rudyerd).

But what of the woman who inspired the name of our woodland warbler? Laura Boulton became a renowned field recordist, filmmaker and collector of traditional musical instruments from around the world. During her life she embarked on almost 30 recording expeditions throughout Africa, Europe, Asia and North America, amassing tens of thousands of sound recordings, photos, films, books and instruments. She experienced first hand advancements in recording technology, beginning her career with an Edison phonograph before progressing to a disc cutting machine and eventually a portable reel to reel recorder. Her legacy can be found in various institutions across the United States, from the Center for Ethnomusicology at Columbia University to the Archives of Traditional Music at Indiana University. 

  One of Boulton's published collections of ethnographic field recordings (BL Shelfmark 1LP0247765)

When beginning my research I never imagined that two such colourful characters would be behind the name of this rather inconspicuous little warbler. Two years after the discovery of Laura's Woodland Warbler, Rudyerd was himself taxonomically immortalised by the American herpetologist Karl Patterson Schmidt, who named a new species of Namib day gecko, Rhoptropus boultoni, in his honour. And in case you're wondering, Schmidt must have liked Rudyerd. Rhoptropus boultoni is a pretty cute gecko.

Follow @CherylTipp for all the latest wildlife news. 

This week's selection comes from Cheryl Tipp, Curator of Wildlife and Environmental Sounds.

The soaring temperatures of summer can have explosive results, especially if you happen to be standing near a gorse bush. This thorny, evergreen shrub produces an unmistakable sea of bright, yellow flowers from January to June. As the flowers begin to fade, a mass of black seed pods emerge to take their place. Slowly but surely, the heat of the summer sun dries out these downy carriers until the structures burst open, expelling the tiny seeds enclosed within. The force of this explosion produces a sharp, popping sound, as can be heard in the following example recorded on the Isle of Wight by Richard Beard.

Exploding seed pods (BL ref 212269)

Gorse seed pods (Photo credit: Starr Environmental on VisualHunt / CC BY)

This recording was chosen in memory of the field recordist Richard Beard (1953-2018) whose work in the wildlife section helped process hundreds of unpublished collections for more than a decade. Richard also contributed many thousands of his own recordings to the British Library, some of which can be heard in the Weather and Water collections on British Library Sounds. An oral history interview with Richard, conducted in 2013, can be found here.

Follow @CherylTipp and @soundarchive for all the latest news.